* [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
@ 2017-02-28 2:19 ` Long Li
0 siblings, 0 replies; 7+ messages in thread
From: Long Li @ 2017-02-28 2:19 UTC (permalink / raw)
To: KY Srinivasan, Haiyang Zhang, Bjorn Helgaas
Cc: devel, linux-pci, linux-kernel
hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove,
the bus is already removed before the call, so we don't need to rescan
the bus in the workqueue scheduled from hv_pci_devices_present. By
introducing status hv_pcibus_removed, we can avoid this situation.
Signed-off-by: Long Li <longli@microsoft.com>
Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
---
drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index a8deeca..4a37598 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -348,6 +348,7 @@ enum hv_pcibus_state {
hv_pcibus_init = 0,
hv_pcibus_probed,
hv_pcibus_installed,
+ hv_pcibus_removed,
hv_pcibus_maximum
};
@@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct work_struct *work)
put_pcichild(hpdev, hv_pcidev_ref_initial);
}
- /* Tell the core to rescan bus because there may have been changes. */
- if (hbus->state == hv_pcibus_installed) {
+ switch (hbus->state) {
+ case hv_pcibus_installed:
+ /*
+ * Tell the core to rescan bus
+ * because there may have been changes.
+ */
pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
- } else {
+ break;
+
+ case hv_pcibus_init:
+ case hv_pcibus_probed:
survey_child_resources(hbus);
+ break;
+
+ default:
+ break;
}
up(&hbus->enum_sem);
@@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
if (!hbus)
return -ENOMEM;
+ hbus->state = hv_pcibus_init;
/*
* The PCI bus "domain" is what is called "segment" in ACPI and
@@ -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
pci_stop_root_bus(hbus->pci_bus);
pci_remove_root_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
+ hbus->state = hv_pcibus_removed;
}
ret = hv_send_resources_released(hdev);
--
1.8.5.6
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
@ 2017-02-28 2:19 ` Long Li
0 siblings, 0 replies; 7+ messages in thread
From: Long Li @ 2017-02-28 2:19 UTC (permalink / raw)
To: KY Srinivasan, Haiyang Zhang, Bjorn Helgaas
Cc: devel, linux-pci, linux-kernel
hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove,
the bus is already removed before the call, so we don't need to rescan=20
the bus in the workqueue scheduled from hv_pci_devices_present. By=20
introducing status hv_pcibus_removed, we can avoid this situation.
Signed-off-by: Long Li <longli@microsoft.com>
Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
---
drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index a8deeca..4a37598 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -348,6 +348,7 @@ enum hv_pcibus_state {
hv_pcibus_init =3D 0,
hv_pcibus_probed,
hv_pcibus_installed,
+ hv_pcibus_removed,
hv_pcibus_maximum
};
=20
@@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct work_st=
ruct *work)
put_pcichild(hpdev, hv_pcidev_ref_initial);
}
=20
- /* Tell the core to rescan bus because there may have been changes. */
- if (hbus->state =3D=3D hv_pcibus_installed) {
+ switch (hbus->state) {
+ case hv_pcibus_installed:
+ /*
+ * Tell the core to rescan bus
+ * because there may have been changes.
+ */
pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
- } else {
+ break;
+
+ case hv_pcibus_init:
+ case hv_pcibus_probed:
survey_child_resources(hbus);
+ break;
+
+ default:
+ break;
}
=20
up(&hbus->enum_sem);
@@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
hbus =3D kzalloc(sizeof(*hbus), GFP_KERNEL);
if (!hbus)
return -ENOMEM;
+ hbus->state =3D hv_pcibus_init;
=20
/*
* The PCI bus "domain" is what is called "segment" in ACPI and
@@ -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
pci_stop_root_bus(hbus->pci_bus);
pci_remove_root_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
+ hbus->state =3D hv_pcibus_removed;
}
=20
ret =3D hv_send_resources_released(hdev);
--=20
1.8.5.6
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
2017-02-28 2:19 ` Long Li
(?)
@ 2017-03-16 20:06 ` Bjorn Helgaas
2017-03-16 21:46 ` Long Li
2017-03-22 23:34 ` Long Li
-1 siblings, 2 replies; 7+ messages in thread
From: Bjorn Helgaas @ 2017-03-16 20:06 UTC (permalink / raw)
To: Long Li
Cc: KY Srinivasan, Haiyang Zhang, Bjorn Helgaas, devel, linux-pci,
linux-kernel
On Tue, Feb 28, 2017 at 02:19:45AM +0000, Long Li wrote:
> hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
> device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove,
> the bus is already removed before the call, so we don't need to rescan
> the bus in the workqueue scheduled from hv_pci_devices_present. By
> introducing status hv_pcibus_removed, we can avoid this situation.
>
> Signed-off-by: Long Li <longli@microsoft.com>
> Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
> Acked-by: K. Y. Srinivasan <kys@microsoft.com>
This didn't apply for me because saving it to a file resulted in some
encoded file with "=3D" instead of "=". I see that mutt is smart enough to
deal with that in this reply, so there's probably a way for it to decode it
when saving to a file, but I don't know it.
I tried to apply it by hand, but the hunk in hv_pci_remove() doesn't match
the context. I think your patch is based on something previous to
17978524a636 ("PCI: hv: Fix hv_pci_remove() for hot-remove"). Please
refresh the patch so it applies to my "master" branch (currently
v4.11-rc1).
Also, the "default: break;" case below is redundant and can be removed.
So I'll wait for your updated versions of both these patches.
> ---
> drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> 1 file changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index a8deeca..4a37598 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> hv_pcibus_init = 0,
> hv_pcibus_probed,
> hv_pcibus_installed,
> + hv_pcibus_removed,
> hv_pcibus_maximum
> };
>
> @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct work_struct *work)
> put_pcichild(hpdev, hv_pcidev_ref_initial);
> }
>
> - /* Tell the core to rescan bus because there may have been changes. */
> - if (hbus->state == hv_pcibus_installed) {
> + switch (hbus->state) {
> + case hv_pcibus_installed:
> + /*
> + * Tell the core to rescan bus
> + * because there may have been changes.
> + */
> pci_lock_rescan_remove();
> pci_scan_child_bus(hbus->pci_bus);
> pci_unlock_rescan_remove();
> - } else {
> + break;
> +
> + case hv_pcibus_init:
> + case hv_pcibus_probed:
> survey_child_resources(hbus);
> + break;
> +
> + default:
> + break;
^ This is redundant.
> }
>
> up(&hbus->enum_sem);
> @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
> if (!hbus)
> return -ENOMEM;
> + hbus->state = hv_pcibus_init;
>
> /*
> * The PCI bus "domain" is what is called "segment" in ACPI and
> @@ -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> pci_stop_root_bus(hbus->pci_bus);
> pci_remove_root_bus(hbus->pci_bus);
> pci_unlock_rescan_remove();
> + hbus->state = hv_pcibus_removed;
> }
>
> ret = hv_send_resources_released(hdev);
> --
> 1.8.5.6
^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
2017-03-16 20:06 ` Bjorn Helgaas
@ 2017-03-16 21:46 ` Long Li
2017-03-22 23:34 ` Long Li
1 sibling, 0 replies; 7+ messages in thread
From: Long Li @ 2017-03-16 21:46 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: KY Srinivasan, Haiyang Zhang, Bjorn Helgaas, devel, linux-pci,
linux-kernel
> -----Original Message-----
> From: Bjorn Helgaas [mailto:helgaas@kernel.org]
> Sent: Thursday, March 16, 2017 1:07 PM
> To: Long Li <longli@microsoft.com>
> Cc: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> <haiyangz@microsoft.com>; Bjorn Helgaas <bhelgaas@google.com>;
> devel@linuxdriverproject.org; linux-pci@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
>
> On Tue, Feb 28, 2017 at 02:19:45AM +0000, Long Li wrote:
> > hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
> > device from host (e.g. by disabling SRIOV on a device). In
> > hv_pci_remove, the bus is already removed before the call, so we don't
> > need to rescan the bus in the workqueue scheduled from
> > hv_pci_devices_present. By introducing status hv_pcibus_removed, we
> can avoid this situation.
> >
> > Signed-off-by: Long Li <longli@microsoft.com>
> > Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
> > Acked-by: K. Y. Srinivasan <kys@microsoft.com>
>
> This didn't apply for me because saving it to a file resulted in some encoded
> file with "=3D" instead of "=". I see that mutt is smart enough to deal with
> that in this reply, so there's probably a way for it to decode it when saving to
> a file, but I don't know it.
>
> I tried to apply it by hand, but the hunk in hv_pci_remove() doesn't match
> the context. I think your patch is based on something previous to
> 17978524a636 ("PCI: hv: Fix hv_pci_remove() for hot-remove"). Please
> refresh the patch so it applies to my "master" branch (currently v4.11-rc1).
>
> Also, the "default: break;" case below is redundant and can be removed.
>
> So I'll wait for your updated versions of both these patches.
Thanks, I'll address those issues and resend the patch.
>
> > ---
> > drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> > 1 file changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-hyperv.c
> > b/drivers/pci/host/pci-hyperv.c index a8deeca..4a37598 100644
> > --- a/drivers/pci/host/pci-hyperv.c
> > +++ b/drivers/pci/host/pci-hyperv.c
> > @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> > hv_pcibus_init = 0,
> > hv_pcibus_probed,
> > hv_pcibus_installed,
> > + hv_pcibus_removed,
> > hv_pcibus_maximum
> > };
> >
> > @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct
> work_struct *work)
> > put_pcichild(hpdev, hv_pcidev_ref_initial);
> > }
> >
> > - /* Tell the core to rescan bus because there may have been changes.
> */
> > - if (hbus->state == hv_pcibus_installed) {
> > + switch (hbus->state) {
> > + case hv_pcibus_installed:
> > + /*
> > + * Tell the core to rescan bus
> > + * because there may have been changes.
> > + */
> > pci_lock_rescan_remove();
> > pci_scan_child_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > - } else {
> > + break;
> > +
> > + case hv_pcibus_init:
> > + case hv_pcibus_probed:
> > survey_child_resources(hbus);
> > + break;
> > +
> > + default:
> > + break;
>
> ^ This is redundant.
>
> > }
> >
> > up(&hbus->enum_sem);
> > @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> > hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
> > if (!hbus)
> > return -ENOMEM;
> > + hbus->state = hv_pcibus_init;
> >
> > /*
> > * The PCI bus "domain" is what is called "segment" in ACPI and @@
> > -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> > pci_stop_root_bus(hbus->pci_bus);
> > pci_remove_root_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > + hbus->state = hv_pcibus_removed;
> > }
> >
> > ret = hv_send_resources_released(hdev);
> > --
> > 1.8.5.6
^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
@ 2017-03-16 21:46 ` Long Li
0 siblings, 0 replies; 7+ messages in thread
From: Long Li @ 2017-03-16 21:46 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: KY Srinivasan, Haiyang Zhang, Bjorn Helgaas, devel, linux-pci,
linux-kernel
> -----Original Message-----
> From: Bjorn Helgaas [mailto:helgaas@kernel.org]
> Sent: Thursday, March 16, 2017 1:07 PM
> To: Long Li <longli@microsoft.com>
> Cc: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> <haiyangz@microsoft.com>; Bjorn Helgaas <bhelgaas@google.com>;
> devel@linuxdriverproject.org; linux-pci@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
>=20
> On Tue, Feb 28, 2017 at 02:19:45AM +0000, Long Li wrote:
> > hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
> > device from host (e.g. by disabling SRIOV on a device). In
> > hv_pci_remove, the bus is already removed before the call, so we don't
> > need to rescan the bus in the workqueue scheduled from
> > hv_pci_devices_present. By introducing status hv_pcibus_removed, we
> can avoid this situation.
> >
> > Signed-off-by: Long Li <longli@microsoft.com>
> > Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
> > Acked-by: K. Y. Srinivasan <kys@microsoft.com>
>=20
> This didn't apply for me because saving it to a file resulted in some enc=
oded
> file with "=3D3D" instead of "=3D". I see that mutt is smart enough to d=
eal with
> that in this reply, so there's probably a way for it to decode it when sa=
ving to
> a file, but I don't know it.
>=20
> I tried to apply it by hand, but the hunk in hv_pci_remove() doesn't matc=
h
> the context. I think your patch is based on something previous to
> 17978524a636 ("PCI: hv: Fix hv_pci_remove() for hot-remove"). Please
> refresh the patch so it applies to my "master" branch (currently v4.11-rc=
1).
>=20
> Also, the "default: break;" case below is redundant and can be removed.
>=20
> So I'll wait for your updated versions of both these patches.
Thanks, I'll address those issues and resend the patch.
>=20
> > ---
> > drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> > 1 file changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-hyperv.c
> > b/drivers/pci/host/pci-hyperv.c index a8deeca..4a37598 100644
> > --- a/drivers/pci/host/pci-hyperv.c
> > +++ b/drivers/pci/host/pci-hyperv.c
> > @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> > hv_pcibus_init =3D 0,
> > hv_pcibus_probed,
> > hv_pcibus_installed,
> > + hv_pcibus_removed,
> > hv_pcibus_maximum
> > };
> >
> > @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct
> work_struct *work)
> > put_pcichild(hpdev, hv_pcidev_ref_initial);
> > }
> >
> > - /* Tell the core to rescan bus because there may have been changes.
> */
> > - if (hbus->state =3D=3D hv_pcibus_installed) {
> > + switch (hbus->state) {
> > + case hv_pcibus_installed:
> > + /*
> > + * Tell the core to rescan bus
> > + * because there may have been changes.
> > + */
> > pci_lock_rescan_remove();
> > pci_scan_child_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > - } else {
> > + break;
> > +
> > + case hv_pcibus_init:
> > + case hv_pcibus_probed:
> > survey_child_resources(hbus);
> > + break;
> > +
> > + default:
> > + break;
>=20
> ^ This is redundant.
>=20
> > }
> >
> > up(&hbus->enum_sem);
> > @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> > hbus =3D kzalloc(sizeof(*hbus), GFP_KERNEL);
> > if (!hbus)
> > return -ENOMEM;
> > + hbus->state =3D hv_pcibus_init;
> >
> > /*
> > * The PCI bus "domain" is what is called "segment" in ACPI and @@
> > -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> > pci_stop_root_bus(hbus->pci_bus);
> > pci_remove_root_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > + hbus->state =3D hv_pcibus_removed;
> > }
> >
> > ret =3D hv_send_resources_released(hdev);
> > --
> > 1.8.5.6
^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
2017-03-16 20:06 ` Bjorn Helgaas
@ 2017-03-22 23:34 ` Long Li
2017-03-22 23:34 ` Long Li
1 sibling, 0 replies; 7+ messages in thread
From: Long Li @ 2017-03-22 23:34 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: KY Srinivasan, Haiyang Zhang, Bjorn Helgaas, devel, linux-pci,
linux-kernel
> -----Original Message-----
> From: Bjorn Helgaas [mailto:helgaas@kernel.org]
> Sent: Thursday, March 16, 2017 1:07 PM
> To: Long Li <longli@microsoft.com>
> Cc: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> <haiyangz@microsoft.com>; Bjorn Helgaas <bhelgaas@google.com>;
> devel@linuxdriverproject.org; linux-pci@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
>
> On Tue, Feb 28, 2017 at 02:19:45AM +0000, Long Li wrote:
> > hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
> > device from host (e.g. by disabling SRIOV on a device). In
> > hv_pci_remove, the bus is already removed before the call, so we don't
> > need to rescan the bus in the workqueue scheduled from
> > hv_pci_devices_present. By introducing status hv_pcibus_removed, we
> can avoid this situation.
> >
> > Signed-off-by: Long Li <longli@microsoft.com>
> > Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
> > Acked-by: K. Y. Srinivasan <kys@microsoft.com>
>
> This didn't apply for me because saving it to a file resulted in some encoded
> file with "=3D" instead of "=". I see that mutt is smart enough to deal with
> that in this reply, so there's probably a way for it to decode it when saving to
> a file, but I don't know it.
>
> I tried to apply it by hand, but the hunk in hv_pci_remove() doesn't match
> the context. I think your patch is based on something previous to
> 17978524a636 ("PCI: hv: Fix hv_pci_remove() for hot-remove"). Please
> refresh the patch so it applies to my "master" branch (currently v4.11-rc1).
>
> Also, the "default: break;" case below is redundant and can be removed.
>
> So I'll wait for your updated versions of both these patches.
>
> > ---
> > drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> > 1 file changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-hyperv.c
> > b/drivers/pci/host/pci-hyperv.c index a8deeca..4a37598 100644
> > --- a/drivers/pci/host/pci-hyperv.c
> > +++ b/drivers/pci/host/pci-hyperv.c
> > @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> > hv_pcibus_init = 0,
> > hv_pcibus_probed,
> > hv_pcibus_installed,
> > + hv_pcibus_removed,
> > hv_pcibus_maximum
> > };
> >
> > @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct
> work_struct *work)
> > put_pcichild(hpdev, hv_pcidev_ref_initial);
> > }
> >
> > - /* Tell the core to rescan bus because there may have been changes.
> */
> > - if (hbus->state == hv_pcibus_installed) {
> > + switch (hbus->state) {
> > + case hv_pcibus_installed:
> > + /*
> > + * Tell the core to rescan bus
> > + * because there may have been changes.
> > + */
> > pci_lock_rescan_remove();
> > pci_scan_child_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > - } else {
> > + break;
> > +
> > + case hv_pcibus_init:
> > + case hv_pcibus_probed:
> > survey_child_resources(hbus);
> > + break;
> > +
> > + default:
> > + break;
>
> ^ This is redundant.
I found it still needs "default:break", or it will give a compiler warning:
drivers/pci/host/pci-hyperv.c: In function 'pci_devices_present_work':
drivers/pci/host/pci-hyperv.c:1510:2: warning: enumeration value 'hv_pcibus_removed' not handled in switch [-Wswitch]
switch(hbus->state) {
^
drivers/pci/host/pci-hyperv.c:1510:2: warning: enumeration value 'hv_pcibus_maximum' not handled in switch [-Wswitch]
>
> > }
> >
> > up(&hbus->enum_sem);
> > @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> > hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
> > if (!hbus)
> > return -ENOMEM;
> > + hbus->state = hv_pcibus_init;
> >
> > /*
> > * The PCI bus "domain" is what is called "segment" in ACPI and @@
> > -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> > pci_stop_root_bus(hbus->pci_bus);
> > pci_remove_root_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > + hbus->state = hv_pcibus_removed;
> > }
> >
> > ret = hv_send_resources_released(hdev);
> > --
> > 1.8.5.6
^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
@ 2017-03-22 23:34 ` Long Li
0 siblings, 0 replies; 7+ messages in thread
From: Long Li @ 2017-03-22 23:34 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: KY Srinivasan, Haiyang Zhang, Bjorn Helgaas, devel, linux-pci,
linux-kernel
> -----Original Message-----
> From: Bjorn Helgaas [mailto:helgaas@kernel.org]
> Sent: Thursday, March 16, 2017 1:07 PM
> To: Long Li <longli@microsoft.com>
> Cc: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> <haiyangz@microsoft.com>; Bjorn Helgaas <bhelgaas@google.com>;
> devel@linuxdriverproject.org; linux-pci@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove
>=20
> On Tue, Feb 28, 2017 at 02:19:45AM +0000, Long Li wrote:
> > hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
> > device from host (e.g. by disabling SRIOV on a device). In
> > hv_pci_remove, the bus is already removed before the call, so we don't
> > need to rescan the bus in the workqueue scheduled from
> > hv_pci_devices_present. By introducing status hv_pcibus_removed, we
> can avoid this situation.
> >
> > Signed-off-by: Long Li <longli@microsoft.com>
> > Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
> > Acked-by: K. Y. Srinivasan <kys@microsoft.com>
>=20
> This didn't apply for me because saving it to a file resulted in some enc=
oded
> file with "=3D3D" instead of "=3D". I see that mutt is smart enough to d=
eal with
> that in this reply, so there's probably a way for it to decode it when sa=
ving to
> a file, but I don't know it.
>=20
> I tried to apply it by hand, but the hunk in hv_pci_remove() doesn't matc=
h
> the context. I think your patch is based on something previous to
> 17978524a636 ("PCI: hv: Fix hv_pci_remove() for hot-remove"). Please
> refresh the patch so it applies to my "master" branch (currently v4.11-rc=
1).
>=20
> Also, the "default: break;" case below is redundant and can be removed.
>=20
> So I'll wait for your updated versions of both these patches.
>=20
> > ---
> > drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> > 1 file changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-hyperv.c
> > b/drivers/pci/host/pci-hyperv.c index a8deeca..4a37598 100644
> > --- a/drivers/pci/host/pci-hyperv.c
> > +++ b/drivers/pci/host/pci-hyperv.c
> > @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> > hv_pcibus_init =3D 0,
> > hv_pcibus_probed,
> > hv_pcibus_installed,
> > + hv_pcibus_removed,
> > hv_pcibus_maximum
> > };
> >
> > @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct
> work_struct *work)
> > put_pcichild(hpdev, hv_pcidev_ref_initial);
> > }
> >
> > - /* Tell the core to rescan bus because there may have been changes.
> */
> > - if (hbus->state =3D=3D hv_pcibus_installed) {
> > + switch (hbus->state) {
> > + case hv_pcibus_installed:
> > + /*
> > + * Tell the core to rescan bus
> > + * because there may have been changes.
> > + */
> > pci_lock_rescan_remove();
> > pci_scan_child_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > - } else {
> > + break;
> > +
> > + case hv_pcibus_init:
> > + case hv_pcibus_probed:
> > survey_child_resources(hbus);
> > + break;
> > +
> > + default:
> > + break;
>=20
> ^ This is redundant.
I found it still needs "default:break", or it will give a compiler warning:
drivers/pci/host/pci-hyperv.c: In function 'pci_devices_present_work':
drivers/pci/host/pci-hyperv.c:1510:2: warning: enumeration value 'hv_pcibus=
_removed' not handled in switch [-Wswitch]
switch(hbus->state) {
^
drivers/pci/host/pci-hyperv.c:1510:2: warning: enumeration value 'hv_pcibus=
_maximum' not handled in switch [-Wswitch]
>=20
> > }
> >
> > up(&hbus->enum_sem);
> > @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> > hbus =3D kzalloc(sizeof(*hbus), GFP_KERNEL);
> > if (!hbus)
> > return -ENOMEM;
> > + hbus->state =3D hv_pcibus_init;
> >
> > /*
> > * The PCI bus "domain" is what is called "segment" in ACPI and @@
> > -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> > pci_stop_root_bus(hbus->pci_bus);
> > pci_remove_root_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > + hbus->state =3D hv_pcibus_removed;
> > }
> >
> > ret =3D hv_send_resources_released(hdev);
> > --
> > 1.8.5.6
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2017-03-23 1:11 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-02-28 2:19 [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove Long Li
2017-02-28 2:19 ` Long Li
2017-03-16 20:06 ` Bjorn Helgaas
2017-03-16 21:46 ` Long Li
2017-03-16 21:46 ` Long Li
2017-03-22 23:34 ` Long Li
2017-03-22 23:34 ` Long Li
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